Lefty & Nodal
The principal players in left-right patterning
Figure. Lefty1 restricts Nodal expression to the left side.
The expressing areas of nodal (orange dot), lefty1 (blue line)
and lefty2 (light blue dot) in a ventral view of embryo (E8.0)
are summarized. A: anterior; P: posterior
The internal organs of vertebrates show left-right (L-R) asymmetry in their anatomy and physiology. L-R patterning is determined early during development. Lefty and Nodal have been found to be expressed asymmetrically in developing mouse embryo. Both of these proteins are expressed in the lateral plate mesoderm exclusively on the left side; Nodal acts as the left-side determinant, whereas Lefty functions as a feedback inhibitor of Nodal. Lefty1-deficient and Nodal-deficient mice showed a variety of L-R positional defects in visceral organs including left and right isomerism, respectively.
||Dr. Hiroshi Hamada
||(1) Meno C, Shimono A, Saijoh Y, Yashiro K, Mochida K, Ohishi S, Noji S, Kondoh H, Hamada H.
Cell 1998 Aug 7;94(3):287-97
(2) Adachi H, Saijoh Y, Mochida K, Ohishi S, Hashiguchi H, Hirao A, Hamada H.
Genes Dev1999 Jun 15;13(12):1589-600
(3) Saijoh Y, Oki S, Ohishi S, Hamada H.
Dev Biol 2003 Apr 1;256(1):160-72.